Nitroalkyl-piperazines for inhibiting bacteria fungi and nematodes

ABSTRACT

Antimicrobial compositions containing piperazine nitroalkanes useful as soil sterilants and algicides, etc., for agricultural and industrial application.

Ba /811 313 u uwu male: Grier [54] NITROALKYL-PIPERAZINES FOR INHIBITINGBACTERIA FUNGI AND NEMATODES Nathaniel Grier, Eng1ewood, N.J.

Merck & Co., Inc., Rahway, NJ.

June 21, 1968 Division of Ser. No. 457,802, May 21, 1965, Pat. No.3,399,199.

1 July 18,1972

Smi1ey,J. Org Chem., Vol. 23 1958) pp. 1,115- 1,117. Pevekalin,Unsaturated Witro Compounds 1964) p. 20- Butler, .1. Am. Chem. Soc.,Vol. 78 1956) pp. 482- 484.

1 Primary Examiner-Jerome D. Goldberg US. Cl ..424/250, 424/232,424/245, yhn Frederick Gerkens and J Jerome Behan 106/15, 117/122,117/l38.5, 117/152, 210/64 Int. Cl. ..A01n 9/22 [571 ABSTRACT Field ofSearch ..424/232, 250, 245 Antimicrobial compositions containing pipeazine nitroa]- kanes useful as soil sterilants and algicides, etc., foragricultural and industrial application.

4 Claims, No Drawings l fl 4 a I a 1 1 and fumigants, and also aspesticides (algicides, insecticides,

ovicides, larvicides and nematocides) and as anthelmintics, and toprocesses for preparing and applying the same industrially,agriculturally and therapeutically.

More specifically, the invention relates to compositions containing, andto process utilizing, various substituted alkylnitro compoundscharacterized by a piperazino group on the B-carbon (the carbonsubstituted by nitro being a) and em-.

braced by the following general formulas:

and theiracid and metal salts. In these formulas, R to R and R' to R canbe the same or different members of the class consisting of hydrogen,alkyl (having one to 30 carbons, straight chain or branched, preferablylower alkyl, i.e. having up to eight carbons) unsubstituted orsubstituted, as by one or more of the four halogens, nitro, amino,loweralkyl-substituted amino, hydroxyl, alkoxy (having one to 30carbons, preferably lower alkoxy), aryl (such as phenyl, naphthyl,fluorenyl, anthracenyl, and phenanthryl), the alkyl (of the alkoxy) andaryl groups being unsubstituted or substituted, as by one or more of thefour halogens, nitro, alkyl up to 30 carbons, preferably one to eight,amino, loweralkyl-substituted amino, and hydroxyl, and alkyl-ether(having one to 30 carbons, preferably lower alkyl-ethers), andaryl-ether groups, the aryl group being as above defined; heterocyclics,such as thienyl, furyl, thiazolyl, pyridyl, oxazolyl and quinolyl, andsubstituted heterocyclics as by fluoro, chloro, bromo or iodo groups,nitro, loweralkyl (up to eight carbons), amino and alkoxy (up to 30carbons but preferably lower alkoxy); R and X to X, can be the same ordifferent members of the group consisting of hydrogen, lower alkyl, aryland aralkyl, all as above defined, carboxy, carboalkoxy andhydroxylalkyl (having up to 30 carbons but preferably up to eightcarbons).

A method of synthesis of compounds of this invention can follow theknown procedure in which aldehydes or ketones are condensed with ana-nitroalkane to form the corresponding nitro-olefin (the nitro groupbeing attached to an olefinic carbon) and water:

| N02 NO:

Catalysts employed for the condensation are usually alkaline such as theinorganic alkalis, organic amines, or quaternary ammonium bases. Theresultant water, and any water employed as reaction medium, can beremoved as an azeotrope with water-immiscible solvents such as benzene,toluene, xylene, carbon tetrachloride, etc., or allowed to remain in thereaction mixture. Many known variations can be employed for thesynthesis. Acidic media have also been used for the preparation of thenitroolefins. For example, glacial acetic acid containing a lowconcentration of amine acetates serves well as a means for effectingthese condensations. Hydrochloric acid and hydrogen chloride gas havealso been used. Some use has been made of strong Lewis acids ascatalysts as well as acidic ion exchange resins.

The second step of the synthesis involves the addition of a secondaryamine in the form of piperazine or substituted piperazine to thea,,B-unsaturated nitro compound. The reaction can be run at a range oftemperature extending from below room temperature, i.e., 0l0C., to ashigh as C; solvents for the addition include the aliphatic alcohols,ketones, and hydrocarbons. Mixtures of these can be used along withwater in varying concentrations. Ethers have been frequently selected asthe solvents of choice. As a general rule, the major limitation as tothe solvent system employed, is that it should be inert toward thereactants. In some instances it is possible to perform the additionusing the reactants as such for the solvent. As is known, a selectivechoice of solvents can be made in those cases where a particularsterospecific mode of addition is desired, which results in a dominantyield of a given isomer.

I have found that the steps of forming the nitroolefin and adding on theamine can with advantage be performed as a single operation by mixingthe keto-containing compound, the nitromethane (or lower nitroalkanehaving up to eight carbons) and the secondary amine and causing them toreact.

The ratio of reactants can be varied within wide limits, usuallystoichiometric amounts are used. However, in the addition ofunsubstituted piperazine to the ethylenic nitro compounds, an unexpectedresult was obtained when ratios of reactants were employed which shouldhave yielded or at least favored adducts consisting of two moles of thenitroolefin and one mole of the piperazine; yet a 1:1 adduct wasobtained. In other instances, when a high ratio of unsubstitutedpiperazine to nitroolefin was employed, the major product ultimatelyobtained unexpectedly consisted of an adduct formed from 1 mole of thepiperazine and 2 moles of the nitroolefin.

I have found that the piperazino adducts of the nitroolefines are usefulas antimicrobial and pesticidal agents for industrial, agricultural andmedical applications; for example, as microbicides and microbistats forthe destruction or control of soil fungi and bacteria and for theprotection of seeds, bulbs and plants, as algicides in the treatment ofpools and ponds, cooling water systems and the like, as nematodicides,insecticides, larvicides and ovicides, and as anthelmintics for theelimination of parasites in animals and humans.

The utility of the compounds as antimicrobial agents is shown not onlyby their activity against bacteria and fungi responsive for stunting thegrowth and even destruction of many types of crop-producing plants, butalso for those causing the degradation and deterioration of many typesof materials. This includes papers, leather, textiles, aqueouspreparations such as latex paints, adhesives, resins, pigmentdispersions and oleoresinous coatings whose films are particularlyvulnerable to the destructive action of fungi. The large economic lossesencountered in paper making operations caused by the accumulation ofbacterial and fungal slimes in various parts of the system can beeliminated to a significant extent by the use of the compounds hereindescribed. In agriculture, a severe problem faced in the raising ofcotton, beans, corn and other crops is the loss of yield per acre due tothe action of soilborne fungi on seed and on the roots of the youngplants. The fungi commonly associated with this are Rhizoctonia andFusarium and Pythium species. Excellent control and elimination of theselosses has been accomplished to a major degree by the use of the adductsherein described as soil sterilants in accordance with the invention.They can also be used on foliage and trees for the control of bacterialand fungal diseases.

It is known that the aryl and certain heterocyclic substitutednitroolefins possess antimicrobial properties. However, when, forexample, l-phenyl-Zmitropropene was applied as a soil sterilant atdosages equivalent to or higher than the piperazine adduct of thepresent invention, complete failure resulted when the application to thesoil was made prior to the planting of cotton, snap beans, lima beansand other crops, whereas for example, N-( l-phenyl-2-nitropropyl)piperazine used at lower equivalent levels afiorded an unusually highdegree of protection.

In other applications the utility of the nitroolefins has been severelylimited because of their high degree of lachrymatory action, andirritation of skin immediately following exposure; their strongchrornophoric nature; their high degree of instability and theirtendency to polymerize and produce black, viscous tars. They also show atendency to hydrolyze in the presence of water and return to theoriginal components, the nitro group acting to promote thisdecomposition. This makes them unsuitable for the preservation ofaqueous coating compositions against bacterial fermentation, as astorage or shelflife protection of three years is required by theindustry.

I have found that compounds prepared by the addition of piperazine orsubstituted piperazine to nitroolefins, and particularly to arylandheterocyclic-substituted nitroolefins, not only possess unusually highantimicrobial and pesticidal and the other activities mentioned above,but offer additional advantages in handling and use over the nitrolefinsbecause they are colorless, practically odorless, have no lachrymatoryaction, and are resistant to hydrolysis and polymerization. Further theyhave particular adaptability to a wide variety of systems by the choiceof aryl or heterocyclic groups, and because of the capacity to formsalts with acids, and with a large variety of metals by simple treatmentin known manner with the acid or with a basic compound of the metal (thehydroxide, carbonate, or bicarbonate), or with other types of compoundsof the metals in the presence of an alkali metal base, since thecompounds are both amines and nitronic acids.

Also, it is known that nitroolefins are not active in alkaline mediumand should not be used with alkali or alkaline agents, and arerecommended for use in media having a pH of less than 7.0. (US. patentto Bousquet et chain US. Pat. already 2,335,384, page 2, lines 56-62). Ihave in fact found that alkaline solutions of nitroolefins, e.g.,l-phenyl-2-nitropropene, are inactive as growth inhibitors. In contrast,and quite unexpectedly, .alkaline solutions of the products of myinvention have enhanced antimicrobial activity and other growth inhibitory properties. keto-containing A wide variety of nitroolefins havingtwo or more carbons in the chain, and preferably from two to eight, areuseful as intermediates in the preparation of compounds employed in thepresent invention. The aromatic akdehydes employed in the preparation ofaryl-substituted nitroolefins include benzaldehyde, substitutedbenzaldehydes, as with one or more methoxy and other loweralkoxy grops(having up to but preferably up to eight carbons), or with hydroxyl,fluoro, chloro, bromo, iodo, nitro, aryl, alkyl and a ralkyl (all asabove defined), and including a plurality of mixed substituents; infact, any substituents can be present which do not prevent thecondensation of the aldehyde group with the nitroparaflin. Aromaticketones capable of condensing with the nitroparaffins to formnitroolefins are equally unseable. Those include benzophenonessubstituted as in the case of benzaldehyde, and other ketones of aryl,aralkyl and heterocyclic nature. The nitroparaffins may be nitromethane,-ethane, -propane, -butane or higher cain alkanes, as ready mentioned,and isomers of these. The nitroolefins which contain heterocyclicsubstituents include those of furan, oxazole, pyridine, quinoline,thiazole, thiophene, indole, and other nuclei and their isomers or theirderivatives which are obtainable from commercial sources or by synthesisand which have aldehyde groups or are available as ketones. Thesealdehydes and ketones can also be substituted in various positions ofthe rings with groups with groups such as those mentioned above, whichdo not prevent condensation with the nitroparaflins. Certain groups inthe deto-containing compound which may compete in the condensationreaction, such as aromatic amino, may first be locked by well-knownmodifications, such as benzoylation or acetylation, and the compoundthen condensed with the nitroparaffin followed by removal of theblocking group from the nitroolefin so produced; or, the final additionof the secondary amine to such nitroolefin can be run and then theblocking group removed. For ease of isolation in other instances acarboxyl substituted nucleus may first be esterified, for example, withmethyl, ethyl or benzyl alcohol, and after condensation and/or addition,saponified to liberate the esterifying alcohol.

Addition of the secondary amine (piperazine or substituted piperan'ne)to the nitroolefin takes place with the nitrogen of the amine linking tothe carbon, designated the ,B-carbon, to the carbon bearing the nitrogroup, and the lone hydrogen of the amine joining the oz-carbon, i.e.the one carrying the nitrogen group, as is illustrated by the followingequation:

the substituents R, to R and R,, and X, to X, being as above defined.

As indicated above, either piperazine itself or substituted piperazinehaving at least one secondary nitrogen can be employed for themanufacture of the adducts. One of the nitrogen atoms of the piperazinemay have its hydrogen replaced as indicated above in the definition of ROne or both of the two ring carbon atoms ortho to one of the nitrogenatoms of the piperazines may be similarly substituted; but both carbonsortho to at least one of the nitrogensmust be unsubstituted. Forexample, 2,6-dimethylpiperazines do not add to nitroolefins, undoubtedlydue to steric factors.

No specific time of reaction can be given which will cover the majorityof the additions. It is possible for the adducts to form as rapidly asthe reactants are mixed or the reaction may require a number of hours. Aparticularly useful method for noting the progress of the addition is tomeasure the disappearance of the nitroolefin. This can be done byspectrophotometric methods in many instances, the unsaturated nitrogroup showing strong absorption characteristics.

The products of the reaction are separated using such techniques asprecipitation, fractional crystallization, or distillation in the caseof liquids, or selective salt formation with I acids or bases.

In the last equation hereinabove, the hydrogen of the amino groupbecomes linked to the a-carbon of the nitroolefin. This hydrogen is oneof the groups listedin the definition for R and R4 hereinabove; and inthe examples of the preparation of the adducts presented hereinbelow,this hydrogen is not replaced by another substituent. However, it can bereplaced (as can R, to R, and R, to R: when any of them is hydrogen) byany of the other groups included in the definitions of such substituentshereinabove either by starting with suitably substituted nitroolefins,or by appropriate after-treatment of the formed piperazino-nitroalkanes,in known manner as illustrated by Examples 27 to 30.

The metal salts referred to above are prepared in known manner andinclude the salts of sodium, potassium, calcium, magnesium, strontium,barium, aluminum, zinc, tin, iron, manganese, cobalt, nickel, arsenic,antimony, bismuth, vanadium, etc.

The following examples illustrated satisfactory methods of thepreparation of the compounds of the invention:

EXAMPLE 1 N-( l-Phenyl-2-nitropropyl) Piperazine A novel synthesis wasaccomplished in which the condensation on to aldehyde and nitroparaffinwere condensed with simultaneous use of the piperazine both as acatalyst and a reactant. The amine served as an effective condesnationcatalyst, and at the same time added on the resultant olefin to fonn theadduct. The desired product was obtained in high yield and good purityin a single step. The procedure was as follows:

15 g. (.2 mole) nitroethane and 21.2 g. (.2 mole) benzaldehyde weredissolved in 50 ml. methanol. To the clear solution there was added 13.8g. (.16 mole) piperazine, anhydrous. Within 2 minutes and withoutexternal heating the temperature rose to 51C. to give a clear, brightyellow solution. In less than 1 hour the mixture became difiicult tostir because of the quantity of product which formed. It was maintainedat 55C. for 3 hours, cooled to 35C., diluted with 75 ml. methanol andfiltered. The product was washed with methanol and air-dried. A yield of36.5 g. was obtained, over 90 percent of the theoretical based onpiperazine.

From the filtrate there could be isolated the 2:1 adduct in less than 5percent yield.

For large scale production the piperazine in methanol solution can beadded gradually to the other reactants to control the exothermicreaction.

We have found that the concentration of reactants influences therelative amounts of adducts which result. For example, when the samereaction is carried out using the same proportions of reactants butincreasing the solvent from 50 ml. to 500 ml., the only product obtainedis the 2:1 adduct. Evidently, at high dilution the 1:1 adduct changesover to the 2:1 compound owing to the higher stability of the latter.

However, although the above-described experiments show that the 1:1adduct is the expected product at high concentration conditions, theopposite result was, nevertheless, obtained in the synthesis of thefollowing two products. The same proportions of reactants were used withthe equivalent of only 50 ml. methanol as the reaction solvent.

EXAlVlPLE 2 N ,N-Bis( 1-p-isopropylphenyl-2-nitropropyl )piperazine 45g. (.6 mole) nitroethane and 88.8 g. (0.6 mole) p-isopropylbenzaldehydewere dissolved in 150 ml. methanol. There were then added to the clearsolution 41.4 g. (.48 mole) piperazine, anhydrous. A cooling bath wasused to moderate the exothermic reaction. In less than 1 hour a heavyprecipitate developed. The mixture was held at 40C. for 4 hours andallowed to cool gradually overnight. At room temperature an additional50 ml. methanol were added and the product separated by filtration, Itwas washed with methanol followed by diethyl ether. A colorless solidresulted; yield 111.5 g. It was the bis-adduct melting at l66l70C. andshowing correct elemental analysis. The melting point could be raised byrecrystallizations.

EXAL [PLE 3 N ,N '-Bis( l-p-methoxyphenyl-2-nitropropyl)piperazine 45 g.(.6 mole) nitroethane and 81.6 g. (0.6 mole) paraanisaldehyde weredissolved in 150 ml. methanol. To this, as in the previous synthesis,there were added 41.4 g. (0.48 mole) piperazine, anhydrous. The reactiontemperature was maintained at 4550C. for 5 hours. The heavy mixture wasdiluted after cooling to room temperature with 50 ml. methanol andsuction-filtered. The so-obtained solid was washed with methanol anddiethyl ether. After thorough drying a yield of 112 g. was obtained. Itmelted at l68l70C. and analyzed in good agreement for the 2:1 adduct.

The last two syntheses give products which were completely unexpected,for during a large part of the reaction of the piperazine is present inlarge excess, especially in view of the fact that the nitroolefin isonly formed gradually. Moreover, the reaction is run with very littlesolvent, just enough to make the mixture stirrable. Both these factorsshould favor the formatlon of the 1:1 adducts; nevertheless, the 2:1adducts (nitroolefinezpiperazine) are obtained.

EXAMPLE 4 N,N-Bis( l-Phenyl-2-nitropropyl)piperazine (2-Nitropropenyl)benzene (3.26 g.) was dissolved with constant stirring in anhydrousether (2.5 ml. Piperazine crystals (0.86 g.) were dissolved in abs.EtOl-l (5 ml.) and added to the clear etheral solution of (2-nitropenyl)benzene; almost immediately a thick white precipitate started toseparate. The reaction was allowed to continue for one-half hour withstirring. The mixture was then filtered and washed with a fewmilliliters (5 to 10 ml.) of anhydrous ether. The crude residue weighed2.80 g. It was recrystallized twice from hot methanol which on coolingyielded white crystals melting sharply at l72-l 73C.

On recrystallization of the above product, and of the other piperazineadducts described hereinafter, at least 2 or 3 times from the samesolvent, the 1:1 piperazinezalkene adduct was converted to some extent(10 percent or less) to the 1:2 adduct even when the reactingproportions were equimolecular.

EXAMPLES N,N-Bis( l-Phenyl-2-nitroethyl)piperazine B-Nitrostyrene (2,98g., 0.02 M) was dissolved in absolute ethanol (25 ml.) with constantstirring at room temperature. Piperazine (0.86 g., 0.01 M) was dissolvedin absolute B011 (5 ml.) and was gradually added to the yellow solutionof [3- nitrostyrene. A white, thick precipitate deposited almostimmediately. Stirring was continued for 15-20 minutes, the mixture wasfiltered, and the residue was washed with a few mls. of ethanol anddried. lt weighed 2.90 g. It was recrystallized from acetone-water,yielding fine crystals which melt sharply at 170172C. The product can berecrystallized also from hot ethyl alcohol.

EXAIVIPLE 6 N,N-Bis( l-p-Chlorophenyl-Z-nitroethyl )piperazinep-Chloro-B-nitro styrene (3.67 g.) was dissolved in anhydrous ether (30rnl.) by constant stirring. Piperazine (0.86 g.) was dissolved inabsolute ethyl alcohol (10 ml.) and the solution was gradually added tothe clear yellow solution of pchloro-B-nitrostyrene. The yellow colorimmediately disappeared, and almost immediately a flocculant white solidseparated. Stirring was continued for one-half hour to complete thereaction, the mixture was filtered, and the residue washed with a fewmls. (5-7) of ether. lt weighed 2.5 g. It was recrystallized from hottoluene, which on cooling of the clear solution gave white crystals,m.p. l30-l 32C.

EXAMPLE 7 1-Piperazino-2-nitropropyl-benzene To a solution of 1.63 g. of(2-nitropropenyl) benzene in dry ether (50 ml.) there was addedgradually an alcoholic solution (5 ml.) of piperazine (0.86 g.) withconstant agitation and cooling in an ice bath. Almost immediately awhite, thick precipitate separated. The mixture was stirred for about 30more minutes, and was then filtered and the residue washed with a fewmilliliters of dry ether. It weighed 1.9 g. The crude material melted at153l55C; recrystallized from hot methanol, it melted at l67C.

EXAMPLE 8 l -Piperazi ne- Z-nitrd l -p-chlorophenyl-propa.ne

The same procedure as with the (2-nitropenyl) benzene of Example 5 wasfollowed, using 1.97 g. of p-chromophenyl-2- nitropropene, and analcoholic solution of piperazine containing 0.86 g. of the amine.

Yield: 2 g.: m.p. of the crude material l5816lC. Twice recrystallizedfrom methanol (hot), it melted at 166-169C.

EXAMPLE 9 N,N-( 1-o-Methoxyphenyl-2-nitropropyl)-piperazine 19.3 G. (0.1mole) o-methoxyphenyl-Z-nitropropene were dissolved in 50 ml. diethylether. To this clear solution without any cooling there was added asolution of 8.6 g. piperam'ne, anhydrous in 30 ml. of methanol. Within 2minutes a turbidity developed and the temperature rose to 28C. After 3hours the precipitated solid was removed by filtration, washed with 50ml. 1:1 methanol-ether mixture and air-dried. Yield, 21.5 30; meltingbegins at 131C, clear yellow liquid forming at 145C. For analysis, 3 g.were washed with 4 X 10 ml. portions methanol-ether (1:1) mixture, 2.8g. were recovered with no change in m.p. It analyzed in excellentagreement with theory for the 1:1 adduct.

EXAMPLE l N,N-Bis( 1-o-Methoxyphenyl-2-nitropropyl)piperazine To analcoholic solution containing 1.93 g. of o-methoxyphenyl-Z-nitropropenethere was gradually added a clear solution of piperazine (0.43 g. ofethanol), the mixture being stirred constantly and cooled in anice-water bath. A thick white precipitate separated; this was wasfiltered, washed with -10 ml. of alcohol and a few drops of ether, anddried. It weighed 1.53 g. It was recrystallized after solution in warmtetrahydrofuran; on cooling the clear solution, white needles separatedwhich melted sharply at l53-l 54C.

EXAMPLE 1 l N,N-Bis( l-p-Methoxyphenyl-2-nitropropyl )piperazine Thiscompound was prepared by the procedure of Example 10, starting with 1.93g. of p-methoxyphenyl nitropropene and 0.43 g. ofpiperazine, yielding1.8 g. offinal product. The compound was recrystallized from methanol,m.p. 12 l-l 24C.

EXAMPLE 1 2 N-Methy-N'-(-Phenyl-Phenyl-2-nitropropyl)piperazine Tophenyl nitropropene (3.26 g.) was added dropwise N- methyl piperazine(2.0 ml.). The reaction flask became fairly warm, and almost immediatelya clear yellow solution resulted, which solidified at room temperaturein a few minutes (5-7 minutes), leaving a faintly yellow solid (2.8 g)which was scraped out of the flask and was very soluble in most organicsolvents. It was recrystallized, using acetonewater; white long needlesseparated which melted sharply at 79-80C.

EXAMPLE 1 3 N,N-Bis( 1-o-Chlorophenyl-2-nitropropyl)piperazine To aclear alcoholic solution ml.) of piperazine (2.1 g., 0.024 M) was addedgradually o-chlorophenyl-Z-nitropropene (9.5 ml. 0.048) with constantagitation. A thick white solid separated during the addition; stirringwas continued for onehalf hour. The solid was filtered, washed with afew milliliters (5-10 ml.) of alcohol-ether (50-50) and dried. Itweighed 1.4 g. It was recrystallized from toluene: white crystals whichmelted at 135-137C.

EXAMPLE l4 N,N-Bis( l-p-Tolyl-2-nitropropyl )piperazine1-p-Tolyl2-nitropropene (1.7 g.) was dissolved in anhydrous ether (15ml.). Piperazine (0.43 g.) was dissolved in ethanol (5 m1.) and theclear solution was added gradually with constant stirring to the ethersolution of the nitropropene, the mixture being cooled in an ice-bath.1mmediately after the addition, turbidity started to appear and a whitesolid separated on stirring and continuous cooling for about one-halfhour. The precipitate was filtered, washed with a few milliliters (5-10m1.) of anhydrous ether, and dried. 1t weighed 1.5 g.

After solution in hot methanol, white crystals deposited on cooling withmelted sharply at 156-l58C.

EXAMPLE 15 N,N-Bis[ l-( 2,4-Dichlorophenyl )-2-nitropropyl]piperazine Toan etheral solution of 2,4-dichlorophenyl-2- nitropropene (2.32 g), anetherolic solution of piperazine (0.46 g.) was added dropwise withconstant agitation and cooling of the mixture on an ice-water bath. Oncompletion of the addition of the piperazine solution a white turbidityappeared and a solution began to deposit stirring and cooling werecontinued for about 30 minutes; the precipitate was filtered, washedwith a few mls. of ether (5-10 ml.) and dried. lt weighed 1.5 g.

EXAMPLE l6 N,N-Bis[ l-(3,4-Dichlorophenyl )-2-nitropropyl]piperazine Toan ethanolic solution of 3.4-dichlorophenyl-2- nitropropene (2.3 g.)there was added a clear alcoholic solution of piperazine (0.43 g.) withconstant stirring and cooling in an ice-water bath. lnstantaneously awhite solid separated; stirring was continued for one-half hour in theice bath, the solid was filtered, washed with ethanol (5-10 ml) twotimes, and dried. It weighed 1.8 g.

It was recrystallized with hot methanol; on cooling, white crystalsseparated which melted at 169-l71C.

EXAlVIPLE l 7 N-( l-o-Chlorophenyl-Z-nitropropyl)piperazine 19.75 g.l-o-chlorophenyl-Z-nitropropene were dissolved in ml. diethyl ether withstirring. 8.6 g. piperazine anhydrous were dissolved in 30 ml. methanoland added through a condenser to the yellow, ethereal propene solution;immediately on addition a white solid separated. Stirring was continuefor 1 hour. The solid was suction filtered, washed with 30 ml. 1:1methanol-ether mixture and air-dried. Yield, 27.2 g.; m.p. 132-135C. ltanalyzed correctly for the 1:1 adduct without further treatment, exceptfor an ether and ethyl alcohol wash.

EXAMPLE 1 8 N,N'-Bisl1-Phenyl-2-nitrobutyl)piperazinel-Phenyl-Z-nitrobutene (3.54 g.) was placed in a 50 ml. round bottomflask and with constant agitation by a magnetic stirrer an ethanolicsolution of anhydrous piperazine (0.86 g.) was added to the clear yellowbutene. The reaction flask was removed to an ice-water bath andagitation was continued for a further period of 1 /2 hours. Within 10-15minutes after addition of the piperazine solution a white turbidityappeared and finally a white solid began to deposit. After the saidperiod of agitation the solid was filtered, washed with 10-15 ml. ofethanol, and dried. The residue weighed 2.32 g. From the mother liquormore solid (0.8 g.) was isolated. The product was recrystallized aftersolution in warm dioxan, m.p. 179-18 2C.

EXAMPLE l9 N,N'-Bis-( 1-[2-Furyl]-2-Nitropropyl)piperazinel-(2-Furyl)-2-nitropropene (3.06 g.) was dissolved with constantstirring at room temperature in diethyl ether (15 ml). To this clearyellow solution a solution of 0.86 g. anhydrous piperazine in 5 ml. ofethyl alcohol was added while the solution was agitated for 25 minutes.Within 5 to 10 minutes after addition of the piperazine, a solid startedto separate; after about one-half hour the material was filtered, washedwith ether (10-15 ml.) and ethanol (10-15 ml) and dried. It weighed 1.23g. The crude product melted at 1 10-1 l 3C. It was recrystallized withtoluene (hot); on cooling the crystalline product precipitated melted at1 16-1 19C.

EXAMPLE 20 N-1-p-Cholorophenyl)-2-Nitropropyl-N'-( 1-Pheny1-2-nitropropyl) piperazine l-Pipera1ino-2nitro-(p-chloro)-phenyl propane(2.83 g.) was dissolved completely in hot methanol ml); a clear solutionwas attained by prolonged heating. Phenyl-Z- nitropropene (1.63 g.) wasadded over a period of 2 minutes to a clear warm pale yellow solutionwith constant stirring and cooling in a water bath at room temperature.The mixture was stirred for about 16 hours at room temperature. Thesolvents were partially removed under reduced pressure obtained by awater pump. Ether (30 ml.) was added but no turbidity was observed; onevaporation of the ether, the alcoholic solution was left at roomtemperature for 48 hours; a white crystalline compound settled in thereaction flask; it was filtered and dried. It weighed 1.26 g. It wasrecrystallized with toluene (hot); on cooling the white crystallinematerial precipitated; it melted at l62-164C.

EXAIVIPLE 21 N( l-Thienyl)-( 2-Nitropropyl)piperazinel-(2-Thienyl)-2-nitropropene (1.69 g.) was dissolved completely in 75ml. of diethyl ether with constant agitation by a magnetic stirrer.Anhydrous piperazine (0.43 g.) was dissolved in ethanol (10 ml.) andadded to the clear solution of the propene; stirring was continued for1% hours; within a few minutes of the addition of the ethanolicpiperazine solution a of solid began to separate. After the stirring wascompleted the solid was filtered, washed with dry diethyl ether (10-l5ml.) and ethanol (-10 ml.) and dried. it weighed 1.3 g.

It was recrystallized after a solution in hot benzene and decolorizedwith charcoal (Norit); on cooling, very light brown crystals separatedwhich melted at 130132C.

EXAMPLE 22 N-( 1-Phenyl-2-Nitropropyl)-2-Methyl Piperazine 3.26 g. of(2-nitropropenyl) benzene were dissolved at room temperature in diethyl(50 ml.) with stirring by a magnetic stirrer; 2-methyl piperazine (2.00g.) was dissolved in ethanol 15 ml.) and the solution was added to theyellow clear ether solution with continued stirring. In about 2 minutesa thick white solid separated, so thick that it could not be stirredeasily; more ml.) ethanol was added and stirring continued for one andone half hours. The solid was filtered, washed with ether-alcohol (-20ml.) twice dried at room temperature and weighed: 400 g., m.p. (crude)125-l29C.

The product was dissolved in warm methanol; on cooling, white crystalsseparated which melted at 139-142C.

EXAMPLE 23 Fusion Synthesis of N,N'-Bis( 1-Phenyl-2-nitropropyl) 3l-Phenyl-Z-nitropropene (14 g., 0.085 mole) was melted in a beaker andto the clear brown liquid at 80C. well ground solid piperazine (3.6 g.,0.0425 mole) was added. The reaction was exothermic, the temperatureclimbs to 120C. Mixing was continued for 10-15 minutes. The light yellowsolid was cooled to room temperature, ground, and washed 3 times withdiethyl ether (50 ml. portions) and dried. Yield 14.2 g. Onrecrystallization from hot toluol white crystals, m.p. l94l 95 C. wereobtained. The compound analyzed for the 2:1 adduct in excellentagreement with theory (2 moles of the l-phenyl-Z- nitropropene to one ofthe piperazine).

EXAMPLE 24 Di-(p-Nitrobenzoic acid) Salt of N,N-Bis(1-Phenyl-2-Nitropropyl )-Piperazine Simultaneous conversion of the 1:1 compound tothe 2:1 compound (2 moles of the nitropropyl compound to 1 mole of theamine) with salt formation is illustrated by the following procedure:

N-(1-phenyl-2-nitropropyl)piperazine (0.824 g.) was dissolved in hotmethanol ml.) and the clear solution added to a methanolic solution ofp-nitrobenzoic acid (0.668 g.). With stirring and scratching fine whiteneedles separated. After cooling and filtering, 1.1 g. of product wasobtained. It was recrystallized from methanol, mp. 207C. Analysis showedit had the composition, C H N O ie the salt of the 2: 1 adduct with 2moles of p-nitrobenzoic acid.

EXAMPLE 25 N-[ 1-( p-methylphenyl )-2-nitropropyl ]piperazine 35.4 g. of1-p-methylphenyl-2-nitropropene were dissolved in ml. diethyl other withagitation at room temperature. 172 g. piperazine, anhydrous, weredissolved in 30 ml. methanol and added to the ether solution. Within 3-5minutes a turbidity appeared and a white solid deposited. Stirring wascontinued for two hours, the solid was filtered off and washed twicewith a methanol-ether mixture (50:50), using 20-30 ml. The product wasair dried, yield, 52 g., m.p. -145C. Without any recrystallization thismaterial analyzed correctly as the 1:1 adduct.

The product was converted to the 2:1 adduct by recrystallizing 2.0 g.from approximately 200 m1. hot methanol. On cooling a white crystallineproduct was obtained; yield 1.3 g., m.p. l52C. which analyzed correctlyfor the 2:1 adduct, N,N'-bis l-p-methylphenyl-2-nitropropyl) piperazine.

EXAMPLE 26 Salicylic Acid Salt of N,N-Bis( l-Phenyl-Z-Nitropropyl)Piperazine N,N-bis( l-phenyl-Z-nitroproyl) piperazine (0.64 g.) wasdissolved in hot methanol (15 ml.). An alcoholic solution of salicylicacid (0.122 g.) was added to the cold solution of piperazine adduct withconstant shaking and cooling. In a few moments a pickish whitecrystalline solid was deposited which was cooled and filtered, washedwith l-2 ml.) of methanol and dried. It was recrystallized from hotisopropanol; the crystals were separated on cooling and melted withdecomposition at 225-226C.

By similar procedures the following additional compounds are obtained inaccordance with the present invention:

a. l-N-Piperazino-Z-nitroll -phenylethane b. l-N-Piperazino-Z-nitro- 1-phenylbutane c. l-N-Piperazino-Z-nitrol -phenylpentane d.l-N-Piperazino-Z-nitro- 1 -pheny1hexanel-N-Piperazino-2-nitro-3-methyl-1-phenylbutane l-N-Piperazino-Z-nitro- 1l-diphenylpropane 2-Piperazino-3-nitro-2-phenylbutane2-N-Piperazino-3-nitro-2-( Z-thienyl) butane i.1-N-Piperazino-2-nitro-1-(2-furyl) propane j.l-N-Piperazino-Z-nitro-1-(4-pyridy1) propane k.l-N-Piperazino-2-nitro-1-(3-pyridyl) propane l.1-N-Piperazino-2-nitrol-( Z-pyridyl) propane m.2-N-Piperazino-3-nitro2-( 3-pyridyl) butane n.1N(N-Phenypiperazino)-2-nitro-l-phenylpropane o. 1-N-(2-Methylpiperazino )-2-nitro- 1 -phenylpropane p. l-N-(2-Hydroxyethylpiperazino)-2-nitro- 1 -phenylpropane q. 1-N-(N'-Ethylpiperazino )-2-nitro 1 -phenylpropane r. 1-N-(2-Methylpiperazino)-2-nitrol 2-thienyl )W propane s.1-N-(N'-Methylpiperazino)-2-nitro-1-(2-thienyl) propane t.1-N-Piperazino-2-nitro- 1 -p-phenylphenylpropane u. 1 -N-Piperazino-2-nitro- 1 -p-phenoxyphenylpropane v. l-N-Piperazino-Z-nitro- 1-p-beneylphenylpropane w.l-N-Piperazino-2-nitro-l-(8-hydroxy-5-quinolyl) propane x.l-N-Piperazino-Z-nitro-1-(7-chloro-8-hydroxy-5-quinolyl) propane y.l-N-Piperazino-2-nitro-(2,4,5-trichlorophenyl) propane z. 1-N-(N-Phenyl-2-rnethylpipera2ino)-2-nitrol -phenylpropane 1. N-(1-pmethoxyphenyl-2-nitropropyl)-N-( 1-omethoxyphenyl-2-nitropropy1)piperazine N-[ l-( 2,4-dichlorophenyl)-2-nitropropyl ]-N-(l-pnitrophenyl-Z-nitropropyl)piperazine 3. N'-(l-phenyl-2-nitropropyl)-N-[ l-( 2-thienyl )-2- nitropropyl]piperazinel-N-Piperazino-2-nitrol 3,4-methylenedioxyphenyl) propane 5.l-N-Piperazino-Z-nitrol 4-carboethoxyphenyl) propane 6. 1,3-Di-(l-N-Piperazino-2-nitroethyl)benzene 7. l,3-Di-(l-N-Piperazino-2-nitropropyl)benzene Among the other substitutednitroalkenes that can form useful adducts with secondary amines may bementioned 1- and Z-(B-nitrostyryl) naphthalene, their -bromo and 5-bromo and 8-nitro derivatives, 1-(,8-nitrostyryI)-2,7-dimethoxy-naphthalene, l-(B-nitrostryryU-B-nitronaphthalene,4-chloro-1-(4-nitro--nitrostyryl) naphthalene, 2-(4-chloro-B-nitrostyryl )-6-methoxynaphthalene, 2-( 4-bromo-B-nitrostyryl)-5-chloro-6-methoxynaphthalene and 4-methyll-(3-nitro-B-nitro-styryl) naphthalene; hydroxynitrostilbenes, such as3-hydroxy-a-nitrostilbene, 4-hydroxy-a-nitrostilbene,3-hydroxy-a'-nitrostilbene, 3-bromo-4-hydroxy-anitrostilbene,3-bromo-2-chloro-4-hydroxy-a'-stilbene, 2- chloro -3-hydroxy-a-,4-dinitrostilbene, 4-hydroxy-a', 4- dinitrostilbene,4'-ethyl-4-hydroxy-a'-nitrostilbene, and analogous compounds prepared asdescribed in U.S. Pat. No. 2,914,570; and the additionally substituteda'-nitrostilbenes described in U.S. Pat. No. 2,855,443.

Still other nitroalkenes which can be reacted with secondary amines inaccordance with the present invention are described in U.S. Pat. Nos.2,335,384, and 2,673,223 (which disclose, among others, 1-[l-cyclohexen-3-yl1-2- nitropropene); U.S. Pat. No. 2,895,869 (whichdiscloses various chlorinated nitroalkenes such as3,3-dichloro-lnitropropene, 1,l,1-trichloro-3-nitro-2-butene, and 1,1,1-trichloro-3-nitro-2-pentene); and in U.S. Pat. No. 2,899,429; and in thearticle by Schales and Graefe, Arylnitroalkenes: A New Group ofAntibacterial agents, J.A.C.S. 74, 4,486-90 1952). All of thesenitroalkenes form antimicrobial adducts with the piperazines abovedescribed and are useful as soil sterilants.

AGRICULTURAL APPLICATIONS Nitroamine l-75% Inert diluent 25-99% (clay,talc, etc.)

CH Both R and R can be replaced by hydroxyalkyl, as by reactingl-phenyll-N-piperazino-Z-nitropropane with two molecules of formaldehydeto yield l-phenyl-l-N'-(N-hydroxymethylpiperazino)-2-hydroxymethyl-2-nitropropane. Procedures forintroducing further substituents into the alkane radical are illustratedby the following:

EXAMPLE 27 N-( l-Phenyl-2-nitro-2-hydroxymethylpropyl)-N-methylpiperazine Treatment ofN-(l-phenyl-2-nitropropyl)-N-methylpiperazine in absolute ethanolcontaining a small amount of sodium ethylate with a percent molar excessof 37 percent aqueous formaldehyde and warming at 40C. for 6 hoursyields the above compound.

EXAMPLE 28 N-( 1-Phenyl-2-nitro-2-dimethylaminomethylpropyl)piperazineCondensation of equimolar amounts of dimethylamine hydrochloride, 37percent aqueous formaldehyde, and N-( lphenyI-Z-nitropropyl) piperazinein anhydrous methyl alcohol, by warming to 40C. for several hours,followed by neutralization of the hydrochloride results in liberation ofthe free base.

EXAMPLE 29 N-( 1,3-Diphenyl-2-nitropropyl) piperazine Equimolarquantities of N-(l-phenyl-Z-nitroethyl) piperazine and sodium ethylateare slurried in warm benzene under anhydrous conditions. Benzyl chlorideis then added dropwise using a 10 percent molar excess. The reactionmixture is maintained at 40C. for 8 hours, cooled and filtered. Thefinal product is washed with benzene, ethyl alcohol and finally water.

EXAMPLE 30 N-( l-Phenyl-2-nitro-2-carbomethoxypropyl)-N-methylpiperazineEquimolar quantities of N'-( l-phenyl-2-nitroethyl) N methyl piperazineand sodium ethylate are slurried in warm benzene under anhydrousconditions. Dry methyl chloroacetate is then added portionwise using a25 percent molar excess. The reaction mixture is stirred at 40C. for 16hours, cooled and filtered. The salt is washed with warm benzene, driedand then slurried in water, followed by neutralization with dilutehydrochloric acid. The final product is washed with water and dried.

Compounds wherein R is, for example, chloro, R is methyl and Rhydroxymethyl are obtained by reacting 2-chloro-B- nitrostyrene withN-methyl (or other alkyl groups)-piperazine, and treating the adductwith ethylene oxide to yield N'-[(1-phenyl-l-chloro-Z-methyl-2-nitro-4-hydroxy) butyl] N- methylpiperazine.

The sodium and potassium salts of the compounds of the invention aregenerally soluble in water; while the salts of the other metals areinsoluble to varying degrees. Suitable procedures for preparing thesodium and potassium salts are described in the following examples.

EXANIPLE 31 Sodium Salt of N l-Phenyl-2-nitropropyl) piperazine 20 gramsof sodium hydroxide (0.5 mole) were dissolved in 375 grams of water.124.5 grams of N-( l-phenyl-2- nitropropyl) piperazine (0.5 mole) wereadded slowly to the agitated solution. Agitation was continued for 2hours, after which time a 27 percent solution of the sodium salt wasobtained.

EXAMPLE 32 Potassium Salt of N-( l-Phenyl-Z-nitropropyl) piperazine Asolution of 5.61 grams of potassium hydroxide (0.1 mole) in 69.4 gramsof water was placed in an Erlenmeyer flask equipped with a magneticstirrer. To it were added 24.9 grams of N-(1-phenyl-2-nitropropyl)piperazine (0.1 mole) slowly and stirring was continued for an hour. Theresulting solution contained 29 percent of the potassium salt.

EXANIPLE 3 3 Potassium Salt in Glycol-Water Solution Since for certainapplications alcoholic or glycolic solutions are preferable, a glycolicsolution of the potassium salt of N- (l-phenyl-2-nitropropyl) piperazinein glycol was prepared as follows: l 1.2 grams of potassium hydroxide(0.2 mole) were added to 40 grams of water and 97 grams of ethyleneglycol and stirred to complete the solution. To this there were added49.8 grams of the piperazine adduct (0.2 mole) and the solution wasstirred for one hour, producing a 29 percent solution of the potassiumsalt in glycol-water.

All of the solutions of Examples 31-33 are antirnicrobially active. Thecompounds described herein can be combined with alkaline or basicantimicrobials without affecting their AGRICULTURAL APPLICATIONSNitroamine Inert diluent (clay, talc, etc.)

The mixtures may be finely powdered, e.g. to the l-lO micron averageparticle size, or be made by blending the already finely powderedingredients.

For application as sterilants the dusts may be applied to the seed andsurrounding soil at the time of planting. The concentration of thesterilant is adjusted to give an effective, nonphytotoxic dosage in thesoil. In general, the coil concentration of nitroamine should be from to25 parts per million (of active ingredient). For most economical andeffective use the dusts can be applied in bands of 6 to 8 inchescentered on the rows just prior to seeding. The material can then berototilled to a depth of several inches. This mode of treatment savesmaterial and protects the root system of young plants by sterilizing thesoil to a diameter of about 8 inches around the forming roots. For theprotection of a given crop, such as cabbage, the band spread ofsterilant can vary from 8 inches for black root disease to 12-15 inchesfor club root disease prevention. Similarly, the depth to which thefungicide should be distributed can vary from 2 to 6 inches.

The wettable powders can be prepared by the addition of 0.1-5 percent ofa wetting agent to the powder blends. Many dispersing agents arecommercially available which are nonphytotoxic at the requiredconcentrations. These may, for example, be alkali metal and amine saltsof sulfated and sulfonated acids, alcohols, and oils, or polyethoxylatedphenols, long chain fatty amine quaternary salts, partial fatty acidesters of polyhydric alcohols, etc. The same types of dispersants can beused in preparing emulsifiable concentrates of the nitroamines inorganic solvents. Many of these agents are available in solvent-solubleform. The manner of application to the soil is similar to the dusts.Spray equipment is used to spread the suspensions or emulsions over thesoil, and by discing the fungicidal agents ca be uniformly distributedto varying depths. Spray application is also effective for bandlimitingthe dosages.

Other agricultural uses for these formulations involve the eradicationof bacterial blights of plants by application to the involved sulfaceareas. The compounds of this invention show high orders of bacterialinhibition and are especially useful for this purpose. Some of thediseases which are of commercial importance in decreasing yield andquality and are controlled by the compositions of the invention are fireblight of apple and pear, bacterial spot on stone fruit, cheny leafspot, walnut blight, common blight of bean, bacterial spot of tomato andpepper, and potato seed piece decay. The effective concentration ofnitroamines required varies from 5-l00 parts per million; they may beapplied as dusts, powder dispersions in water, emulsions in water, or asaqueous dipping baths. Other plant fungal diseases which can becontrolled by treatment with these formulations are fungal in origin,such as the many kinds of powdery mildew and leaf scabs.

For seed treatment, proportions as low as l to 4 ounces perhundredweight to '600 ppm of seed) have been found to be effectiveagainst various fungi. Thus, in the case of N-( I-phenyI-Z-nitropropyl)piperazine, 150 ppm were found not only to besufiicient to protect corn seeds, but also to promote an unusuallyhealthy root growth with an improved rate of germination of healthyseedlings and a higher yield of an improved crop.

PAINT APPLICATIONS The nitroanunes are-highly effective as fungicidesfor protecting paintvfilmsagainst the degradation caused by such fungias Pullularia pullulans and Aspergillus niger. They are particularlyuseful in overcoming another important problem in the paint industry,namely, the preservation of aqueous coatings against bacteria]fermentation during storage. It .is known that the principal systems inuse are particularly vulnerable to such attack; these include coatingsbased on polyvinyl acetate, butadiene-styrene, and acrylic polymers andcopolymers. The other addatives required in the formulation of aqueouscoatings also contribute substantially to aiding the growth of bacteria.These nutrient sources include thickeners, such as cellulosederivatives, casein and lecithin; and also film plasticizers,coalescents, stabilizers, and dispersants. Monomers, by-product salts,and organic liquids are also metabolized by bacteria. Even the pH RANGEAT WHICH THESE coatings are adjusted for maximum stability favorsbacterial growth. Some of the end results of bacterial attack on thesesystems are foul odor development, decreased viscosity, breakdown of thecolloid, and downward shift in pH. In addition, gas evolution withresultant pressure build-up in closed systems has resulted in lids ofcontainers being blown off with scattering of contents.

The nitroamines are particularly advantageous in this application. Theyprovide effective inhibition of microbial growth at relatively lowconcentrations, in the range of 5-100 parts per million, they arecolorless and odorless, so that no interference with coating propertiesoccurs, and are low in toxicity and vapor pressure. An effective useconcentration to insure long shelf-life stability of the coatingcompositions is 0.050.1 percent by weight of the whole composition.

The nitroamines can be finely ground and then incorporated by simplemixing, or preferably, addition can be made at the pigment grindingphase of paint manufacture. This is recommended for aqueous andoleoresinous coating systems. The antimicrobial agents are compatiblewith practically all of the commonly used paint ingredients and unlikethe presently used phenylmercury salts do not undergo degradation orother reactions with sulfide-containing pigments such as lithopone.Moreover, a decided advantage is realized in that the presence ofatmospheric hydrogen sulfide causes no darkening of paint filmspreserved against mildew attack with the nitroamines, whereas themercurials and other metallic agents cause colored sulfides to form.

Another advantage lies in the amphoteric nature of the nitroamines. Inaqueous coating compositions a high degree of compatability exists; thecompounds are fully active at either the acid or alkaline pH conditionsselected in any particular case for maximum colloid stability. Theseinclude polyvinyl acetate, butadiene-styrene, and acrylic coatingcompositions, both homopolymer and co-polymer based. The antimicrobialscan be incorporated in various known interior and exterior paints. Thebutadiene-styrene containing coatings are generally for interior useonly and usually are not closed with an antimicrobial agent for mildewprotection. However, preservatives for in-container inhibition offermentation must be used. A typical known type of outdoor paint whichis protected against fungal by BY the addition thereto of about 0.5percent by weight of, for example, N-( l-phenyl-2-nitropropyl)piperazine, l-piperazino-Z-nitro-l-p-tolylpropane, or N,N'- bis[l-(o-chlorophenyl)-2-nitropropyl] piperazine, by mixing in a blender for3 minutes is the following:

viscosity to 82 KU (Krebs Units) Finished paint: pigment volumeconcentration 4 lbs. oil/gallon 9 lbs. pigment/gallon Filter paperspecimens (1.5 inch squares of No. 30 Whatman filter paper) on whichfilms of the above paint compositions containing the differentnitroamines had been dried, the papers then placed on the surface ofplates of Sabouraud Maltose Agar overlaid with 1.25 ml. of sporesuspension being distributed over the face of the test specimens and theplates incubated at 2830C. and 85-90 percent relative humidity showed nogrowth after 4 weeks; the paint containing the N-l-phenyl-2-nitropropyl) piperazine showing also a zone of inhibitionaround the painted area. is A satisfactory method of incorporation ofthe nitroamines [S by way of solutions. Many of them are soluble in suchorganic solvents as xylene, Stoddard solvent (petroleum distillate, atleast 50 percent distilling at 177C. and all at 210C), toluene, andturpentine, so that solutions containing l-50 percent of these can besimply stirred into oil paints in sufficient amount to give finalconcentrations of from 0.05l.0 percent by weight of total formulation;the dosage is based on the kind of areas in which the coating will beused. For example, the higher level of nitroamines would be required inblister-resistant alkyl coatings containing no zinc oxide for use inwarm humid climates such as the Gulf coast area of the USA. Low levelsare recommended in oil paints containing high loadings of zinc oxidewhich give a glossy hard film on drying. In low humidity areas, e.g. theLos Angeles region, a small concentration of the nitroamine wouldsufiice. A suitable method for detemtining dosage is that of J. Ramp andN. Grier (Fungicides in paints. Official Digest, Journal of PaintTechnology and Engineering, Volume 33, September, 1961.)

The solvent solutions described can be made suitable for use inwater-based coatings by incorporating a small percentage of emulsifyingagent, usually 25 percent, and a small amount of coupling solvent, i.e.having both oil and water solubility, such as the lower alcohols,glycols, glycol ethers, dioxane, and the like, in concentrations of upto 10 percent of the total antimicrobial solution. This type ofpreparation can also be used in the oleoresinous systems withoutproducing harmful effects on film properties.

Another mode of adding the nitroamines to aqueous coatings is by use ofalkaline solution in water or water-alcohol. The nitroamines are readilydissolved in the nitronic acid form by the aid of alkaline reagents suchas the inorganic alkalis like sodium hydroxide, potassium hydroxide andammonium hydroxide, and by water-soluble amines, preferably tertiary,for maximum stability of the initial solutions.

ANTl-[ELMINTIC APPLICATIONS Piperazine itself will control ascarids inpoultry, swine, dogs, cats, horses and other animals. It will controlnodular worms in swine, sheep and cattle; and pin worms and certainStrongyle species in horsesaccording to Dow Chemical Companys technicalliterature. The nitroamines fonned from piperazine have been found topossess enhanced piperazine activity. They can be used at the samedosages, weight for weight, as is recommended for piperazine, but thenitroamines correspond to a lower piperazine content, eg N-l-phenyl-Z-nitro-propylpiperazine contains only 34 percent by weight of piperazine,but in view of its higher activity, the same dosage as is recommendedfor piperazine will usually be found to be adequate.

FOR ANIMAL NIEDICATED FEED A dosage of 4 lbs. of the nitroarnine per tonof feed can be used. Usually, the drug is first premixed with one of thefeed ingredients to insure good distribution. The concentration of thenitroarnine in the feed is thus 0.2 percent by weight. The nitroamine isfinely powdered prior to blending.

Swine 2% lbs. of the 0.2 percent feed for every 50 lbs. body weight.

Poultry chickens and turkeys less than 10 weeks old (6-9 weeks old): 5lbs. of 0.2 percent feed for every 50 birds. chickens over 10 weeks old;5 lbs. 0.2 percent feed for every 40 birds.

turkeys over 10 weeks old: 5 lbs. 0.2 percent feed for every 25 birds.

Dogs and Cats 0.] gm. for every 1 lb. of body weight gms. 0.2 percentfeed.

Horses 0.1 g. for every 1 lb. of body weight (50 g. 0.2 percent feed).

Drinking water can be medicated and substituted for medicated feed atequivalent drug/body weight dosage. The concentration of medicament inthe drinking water should be approximately one-half that in the feed toinsure acceptance. Solution of the nitroarnine in water to the extent of0.1 percent can be obtained by the use of either acids such asphosphoric, citric, or tartaric, or alkalis. In either case the dosedwater can be sweetened to secure acceptance by the animals.

The nitroamines present a distinct advantage over piperazine itself froma handling consideration. piperazine, anhydrous, sold as such for use infeed, is extremely hygroscopic. It readily forms a hexahydrate andcontinues to pick up atmospheric moisture; this can cause problems ofstorage; e.g. caking, and also the absorption of carbon dioxide.Transfer of anhydrous piperazine by farm help introduces an additionhazard; the compound is highly alkaline, readily soluble in sweat andcauses severe skin and eye burns on contact. The nitroamines arenon-hygroscopic, poorly soluble in water and relatively free fromhandling hazards. Thus, no caking of treated feed occurs, carbon dioxideis not absorbed, and ordinary handling precautions by unskilled helpsuffice.

INSECI'ICIDAL APPLICATTONS The products of this invention, such as1-piperazino-2-nitrol-(p-chlorophenyl)propane,l-(Z-methylpiperazine)-2-nitrol-phenylpropane,l-nitro-2-(N-piperazino)-3,3- dichloropropane, 1l,1-trichloro-2-N-piperazino)-3-nitrobutane, and1,1,1-trichloro-2-(N-piperazino)3-nitropentane, can be dissolved invarious solvents such as the chlorinated hydrocarbons (chloroform,carbon tetrachloride, tetrachloroethylene), the aliphatic alcohols(methyl, ethyl, propyl, isopropyl, butyl), benzyl alcohol, the aromaticsolvents (benzene, toluene, xylene), or in typical kerosene blends insufficient concentrations e.g. 0.5-5.0 percent to cause knockdown and/ordeath to various insects and pests. These include the common horsefly,mites, beetles, caterpillars, milkweed bugs, aphids, nematodes, insectlarvae, and the like.

The compounds of the 72 can be used in the form of aqueous suspensionsor emulsions, the products being generally insoluble in water. For thistype of formulation various powdered carries can be employed to aid inachieving uniform distribution. Talc, fullers earth, calcium silicate,calcium carbonate, clays and the like are admixed with the insecticidalagent along with wetting and dispersing agents and sticking agents. Formaximum chemical compatibility those which are non-ionic in characterare preferred. Anionic surfactants, such as sodium lauryl sulfate orsodium ligninsulfonate are also satisfactory.

ln tests on nematodes (Panagrellus) suspended in water (30 to 50individuals), the compounds N-1-( l-phenyl-Z- nitropropyl) piperazine,N-l-[1-(o-chlorophenyl)-2- nitropropyl] piperazine, andN-l-[l-(p-tolyl)-2-nitropropyl] piperazine were all found to besubstantially equal in potency to hexyl resorcinol at concenteations of0.1 to 0.0001 percent, there being a 100 percent kill with all thesecompounds at concentrations of 0.1 and 0.01 percent, while for allcompounds, including the comparison compound, the kill fell tosubstantially that of the control suspension or concentrations of 0.001and 0.0001 percent.

For certain uses, particularly as nematocides or as a general soilpesticide, it is desirable that the compounds employed have asufficiently high vapor pressure to diffuse as a vapor throughout thesoil and thus act as a fumigant. It is accordingly within the ambit ofthe invention to employ nitroalkenes which are so substituted that theyhave an increased vapor pressure over aryl-substituted alkenes. Thusadducts of higher vapor pressure will be obtained by employing knownhalogenated nitroalkenes devoid of an aryl group and heretoforesuggested for use as nematocides. See the patent to Bluestone US. Pat.No. 2,895,869, dated July 21, 1959.

USE IN PAPER MILLS Compounds of the invention have been found to beefi'ective also against the organisms that cause slime and deteriorationof pulp and paper mills. Thus, tested against the following organisms:

Alcaligenes vzlrcolactis, ATCC 337,24 hour cultures,

Bacillus subtilis, 24 hour culture,

Salmonella typhosa, ATCC 6539, 24 hour culture,

Staphylococcus aureus, ATCC 6538, 24 hour culture, the compound N-(lphenyl-2-nitropropyl) piperazine inhibited growth at concentrations ofabout 20 to 40 ppm.

The nitrogens of the piperazino moiety can be quaternized to yieldcompounds having properties similar to the bases. Thus, the compoundscan be treated with ethyl chloride, benzyl chloride, ethyl sulfate andother quaternizing agents in known manner. Also, acid salts, as alreadyindicated, can be formed of the bases; for example, the hydrochloric,sulfuric, phosphoric, p-toluenesulfonic and the acid salts of N-(l-phenyl-2-nitropropyl) piperazine. Also, because of the nitronic acidgroup, various amine salts can be prepared in known manner, such assalts with triethanolamine, triethyl amine, tributylamine,tripropanolarnine and the like.

There is described hereinabove the formation of the salicylic acid saltof one of the active compounds of the invention. In analogous fashionthere can be prepared also the hydrochloride, p-toluene sulfonate,phosphate, sulfopalmitate and other acid salts, of such compound and ofthe other compounds embraced by the present invention.

1 claim:

1. The method of inhibiting the growth of bacteria, fungi and nematodesin soil which comprises applying to the soil an efiective amount forinhibiting the growth of bacteria, fungi and nematodes of a compound ofthe formula:

wherein A is hydrogen, loweralkyl or hydroxyloweralkyl; B is wherein R,,R and R are hydrogen, Q, loweralkyl, or substituted loweralkyl whereinthe substituent is halo;

where:

Q is phenyl or substituted phenyl wherein the substituents areloweralkyl, loweralkoxy, loweralkylenedioxy, carboxyloweralkoxy, phenyl,phenoxy, phenylloweralkyl, halo, p-nitro or tolyl;

naphthyl or substituted naphthyl wherein the substituents areloweralkyl, loweralkoxy, halo or nitno;

cyclohexyl;

a heterocyclic radical selected from the group consisting of fury],pyridyl and thienyl;

quinolinyl or substituted quinolinyl wherein the substitutents arehydroxy or chloro; C is B, phenyl, loweralkyl or hydrogen; and providedthat where A is other than hydrogen, C is other than B.

2. The method of claim 1 wherein the compound is N-(lphenyl-2-nitropropyl)piperazine.

3. A composition for inhibiting the growth of bacteria, fungi andnematodes comprising an effective amount for inhibiting the growth ofbacteria, fungi and nematodes of a compound of the formula;

A N I C wherein A is hydrogen loweralkyl or hydroxyloweralkyl; B is R2R1A1CHRS wherein R R and R are hydrogen, Q, loweralkyl, or substitutedloweralkyl wherein the substituent is halo; where:

Q is phenyl or substituted phenyl wherein the substitutents

2. The method of claim 1 wherein the compound isN-(1-phenyl-2-nitropropyl)piperazine.
 3. A composition for inhibitingthe growth of bacteria, fungi and nematodes comprising an effectiveamount for inhibiting the growth of bacteria, fungi and nematodes of acompound of the formula;
 4. A composition of claim 3 wherein thecompound is N-(1-phenyl-2-nitropropyl)piperazine.
 4. A composition ofclaim 3 wherein n the compound is N-(1phenyl-2-nitropropyl)piperazine.